kubernetes/federation/pkg/federation-controller/namespace/namespace_controller.go

/*
Copyright 2016 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package namespace

import (
	"fmt"
	"reflect"
	"time"

	federation_api "k8s.io/kubernetes/federation/apis/federation/v1beta1"
	federationclientset "k8s.io/kubernetes/federation/client/clientset_generated/federation_release_1_5"
	"k8s.io/kubernetes/federation/pkg/federation-controller/util"
	"k8s.io/kubernetes/federation/pkg/federation-controller/util/eventsink"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/errors"
	api_v1 "k8s.io/kubernetes/pkg/api/v1"
	"k8s.io/kubernetes/pkg/client/cache"
	kubeclientset "k8s.io/kubernetes/pkg/client/clientset_generated/release_1_5"
	"k8s.io/kubernetes/pkg/client/record"
	"k8s.io/kubernetes/pkg/controller"
	pkg_runtime "k8s.io/kubernetes/pkg/runtime"
	"k8s.io/kubernetes/pkg/util/flowcontrol"
	"k8s.io/kubernetes/pkg/util/sets"
	"k8s.io/kubernetes/pkg/watch"

	"github.com/golang/glog"
)

const (
	allClustersKey = "ALL_CLUSTERS"
)

type NamespaceController struct {
	// For triggering single namespace reconciliation. This is used when there is an
	// add/update/delete operation on a namespace in either federated API server or
	// in some member of the federation.
	namespaceDeliverer *util.DelayingDeliverer

	// For triggering all namespaces reconciliation. This is used when
	// a new cluster becomes available.
	clusterDeliverer *util.DelayingDeliverer

	// Contains namespaces present in members of federation.
	namespaceFederatedInformer util.FederatedInformer
	// For updating members of federation.
	federatedUpdater util.FederatedUpdater
	// Definitions of namespaces that should be federated.
	namespaceInformerStore cache.Store
	// Informer controller for namespaces that should be federated.
	namespaceInformerController cache.ControllerInterface

	// Client to federated api server.
	federatedApiClient federationclientset.Interface

	// Backoff manager for namespaces
	namespaceBackoff *flowcontrol.Backoff

	// For events
	eventRecorder record.EventRecorder

	namespaceReviewDelay  time.Duration
	clusterAvailableDelay time.Duration
	smallDelay            time.Duration
	updateTimeout         time.Duration
}

// NewNamespaceController returns a new namespace controller
func NewNamespaceController(client federationclientset.Interface) *NamespaceController {
	broadcaster := record.NewBroadcaster()
	broadcaster.StartRecordingToSink(eventsink.NewFederatedEventSink(client))
	recorder := broadcaster.NewRecorder(api.EventSource{Component: "federated-namespace-controller"})

	nc := &NamespaceController{
		federatedApiClient:    client,
		namespaceReviewDelay:  time.Second * 10,
		clusterAvailableDelay: time.Second * 20,
		smallDelay:            time.Second * 3,
		updateTimeout:         time.Second * 30,
		namespaceBackoff:      flowcontrol.NewBackOff(5*time.Second, time.Minute),
		eventRecorder:         recorder,
	}

	// Build delivereres for triggering reconciliations.
	nc.namespaceDeliverer = util.NewDelayingDeliverer()
	nc.clusterDeliverer = util.NewDelayingDeliverer()

	// Start informer in federated API servers on namespaces that should be federated.
	nc.namespaceInformerStore, nc.namespaceInformerController = cache.NewInformer(
		&cache.ListWatch{
			ListFunc: func(options api.ListOptions) (pkg_runtime.Object, error) {
				versionedOptions := util.VersionizeV1ListOptions(options)
				return client.Core().Namespaces().List(versionedOptions)
			},
			WatchFunc: func(options api.ListOptions) (watch.Interface, error) {
				versionedOptions := util.VersionizeV1ListOptions(options)
				return client.Core().Namespaces().Watch(versionedOptions)
			},
		},
		&api_v1.Namespace{},
		controller.NoResyncPeriodFunc(),
		util.NewTriggerOnAllChanges(func(obj pkg_runtime.Object) { nc.deliverNamespaceObj(obj, 0, false) }))

	// Federated informer on namespaces in members of federation.
	nc.namespaceFederatedInformer = util.NewFederatedInformer(
		client,
		func(cluster *federation_api.Cluster, targetClient kubeclientset.Interface) (cache.Store, cache.ControllerInterface) {
			return cache.NewInformer(
				&cache.ListWatch{
					ListFunc: func(options api.ListOptions) (pkg_runtime.Object, error) {
						versionedOptions := util.VersionizeV1ListOptions(options)
						return targetClient.Core().Namespaces().List(versionedOptions)
					},
					WatchFunc: func(options api.ListOptions) (watch.Interface, error) {
						versionedOptions := util.VersionizeV1ListOptions(options)
						return targetClient.Core().Namespaces().Watch(versionedOptions)
					},
				},
				&api_v1.Namespace{},
				controller.NoResyncPeriodFunc(),
				// Trigger reconciliation whenever something in federated cluster is changed. In most cases it
				// would be just confirmation that some namespace opration succeeded.
				util.NewTriggerOnMetaAndSpecChanges(
					func(obj pkg_runtime.Object) { nc.deliverNamespaceObj(obj, nc.namespaceReviewDelay, false) },
				))
		},

		&util.ClusterLifecycleHandlerFuncs{
			ClusterAvailable: func(cluster *federation_api.Cluster) {
				// When new cluster becomes available process all the namespaces again.
				nc.clusterDeliverer.DeliverAfter(allClustersKey, nil, nc.clusterAvailableDelay)
			},
		},
	)

	// Federated updeater along with Create/Update/Delete operations.
	nc.federatedUpdater = util.NewFederatedUpdater(nc.namespaceFederatedInformer,
		func(client kubeclientset.Interface, obj pkg_runtime.Object) error {
			namespace := obj.(*api_v1.Namespace)
			_, err := client.Core().Namespaces().Create(namespace)
			return err
		},
		func(client kubeclientset.Interface, obj pkg_runtime.Object) error {
			namespace := obj.(*api_v1.Namespace)
			_, err := client.Core().Namespaces().Update(namespace)
			return err
		},
		func(client kubeclientset.Interface, obj pkg_runtime.Object) error {
			namespace := obj.(*api_v1.Namespace)
			err := client.Core().Namespaces().Delete(namespace.Name, &api_v1.DeleteOptions{})
			return err
		})
	return nc
}

func (nc *NamespaceController) Run(stopChan <-chan struct{}) {
	go nc.namespaceInformerController.Run(stopChan)
	nc.namespaceFederatedInformer.Start()
	go func() {
		<-stopChan
		nc.namespaceFederatedInformer.Stop()
	}()
	nc.namespaceDeliverer.StartWithHandler(func(item *util.DelayingDelivererItem) {
		namespace := item.Value.(string)
		nc.reconcileNamespace(namespace)
	})
	nc.clusterDeliverer.StartWithHandler(func(_ *util.DelayingDelivererItem) {
		nc.reconcileNamespacesOnClusterChange()
	})
	util.StartBackoffGC(nc.namespaceBackoff, stopChan)
}

func (nc *NamespaceController) deliverNamespaceObj(obj interface{}, delay time.Duration, failed bool) {
	namespace := obj.(*api_v1.Namespace)
	nc.deliverNamespace(namespace.Name, delay, failed)
}

// Adds backoff to delay if this delivery is related to some failure. Resets backoff if there was no failure.
func (nc *NamespaceController) deliverNamespace(namespace string, delay time.Duration, failed bool) {
	if failed {
		nc.namespaceBackoff.Next(namespace, time.Now())
		delay = delay + nc.namespaceBackoff.Get(namespace)
	} else {
		nc.namespaceBackoff.Reset(namespace)
	}
	nc.namespaceDeliverer.DeliverAfter(namespace, namespace, delay)
}

// Check whether all data stores are in sync. False is returned if any of the informer/stores is not yet
// synced with the corresponding api server.
func (nc *NamespaceController) isSynced() bool {
	if !nc.namespaceFederatedInformer.ClustersSynced() {
		glog.V(2).Infof("Cluster list not synced")
		return false
	}
	clusters, err := nc.namespaceFederatedInformer.GetReadyClusters()
	if err != nil {
		glog.Errorf("Failed to get ready clusters: %v", err)
		return false
	}
	if !nc.namespaceFederatedInformer.GetTargetStore().ClustersSynced(clusters) {
		return false
	}
	return true
}

// The function triggers reconciliation of all federated namespaces.
func (nc *NamespaceController) reconcileNamespacesOnClusterChange() {
	if !nc.isSynced() {
		nc.clusterDeliverer.DeliverAfter(allClustersKey, nil, nc.clusterAvailableDelay)
	}
	for _, obj := range nc.namespaceInformerStore.List() {
		namespace := obj.(*api_v1.Namespace)
		nc.deliverNamespace(namespace.Name, nc.smallDelay, false)
	}
}

func (nc *NamespaceController) reconcileNamespace(namespace string) {
	if !nc.isSynced() {
		nc.deliverNamespace(namespace, nc.clusterAvailableDelay, false)
		return
	}

	baseNamespaceObj, exist, err := nc.namespaceInformerStore.GetByKey(namespace)
	if err != nil {
		glog.Errorf("Failed to query main namespace store for %v: %v", namespace, err)
		nc.deliverNamespace(namespace, 0, true)
		return
	}

	if !exist {
		// Not federated namespace, ignoring.
		return
	}
	baseNamespace := baseNamespaceObj.(*api_v1.Namespace)
	if baseNamespace.DeletionTimestamp != nil {
		if err := nc.delete(baseNamespace); err != nil {
			glog.Errorf("Failed to delete %s: %v", namespace, err)
			nc.eventRecorder.Eventf(baseNamespace, api.EventTypeNormal, "DeleteFailed",
				"Namespace delete failed: %v", err)
			nc.deliverNamespace(namespace, 0, true)
		}
		return
	}

	clusters, err := nc.namespaceFederatedInformer.GetReadyClusters()
	if err != nil {
		glog.Errorf("Failed to get cluster list: %v", err)
		nc.deliverNamespace(namespace, nc.clusterAvailableDelay, false)
		return
	}

	operations := make([]util.FederatedOperation, 0)
	for _, cluster := range clusters {
		clusterNamespaceObj, found, err := nc.namespaceFederatedInformer.GetTargetStore().GetByKey(cluster.Name, namespace)
		if err != nil {
			glog.Errorf("Failed to get %s from %s: %v", namespace, cluster.Name, err)
			nc.deliverNamespace(namespace, 0, true)
			return
		}
		desiredNamespace := &api_v1.Namespace{
			ObjectMeta: util.CopyObjectMeta(baseNamespace.ObjectMeta),
			Spec:       baseNamespace.Spec,
		}

		if !found {
			nc.eventRecorder.Eventf(baseNamespace, api.EventTypeNormal, "CreateInCluster",
				"Creating namespace in cluster %s", cluster.Name)

			operations = append(operations, util.FederatedOperation{
				Type:        util.OperationTypeAdd,
				Obj:         desiredNamespace,
				ClusterName: cluster.Name,
			})
		} else {
			clusterNamespace := clusterNamespaceObj.(*api_v1.Namespace)

			// Update existing namespace, if needed.
			if !util.ObjectMetaEquivalent(desiredNamespace.ObjectMeta, clusterNamespace.ObjectMeta) ||
				!reflect.DeepEqual(desiredNamespace.Spec, clusterNamespace.Spec) {
				nc.eventRecorder.Eventf(baseNamespace, api.EventTypeNormal, "UpdateInCluster",
					"Updating namespace in cluster %s", cluster.Name)

				operations = append(operations, util.FederatedOperation{
					Type:        util.OperationTypeUpdate,
					Obj:         desiredNamespace,
					ClusterName: cluster.Name,
				})
			}
		}
	}

	if len(operations) == 0 {
		// Everything is in order
		return
	}
	err = nc.federatedUpdater.UpdateWithOnError(operations, nc.updateTimeout, func(op util.FederatedOperation, operror error) {
		nc.eventRecorder.Eventf(baseNamespace, api.EventTypeNormal, "UpdateInClusterFailed",
			"Namespace update in cluster %s failed: %v", op.ClusterName, operror)
	})
	if err != nil {
		glog.Errorf("Failed to execute updates for %s: %v", namespace, err)
		nc.deliverNamespace(namespace, 0, true)
		return
	}

	// Evertyhing is in order but lets be double sure
	nc.deliverNamespace(namespace, nc.namespaceReviewDelay, false)
}

// delete  deletes the given namespace or returns error if the deletion was not complete.
func (nc *NamespaceController) delete(namespace *api_v1.Namespace) error {
	// Set Terminating status.
	updatedNamespace := &api_v1.Namespace{
		ObjectMeta: namespace.ObjectMeta,
		Spec:       namespace.Spec,
		Status: api_v1.NamespaceStatus{
			Phase: api_v1.NamespaceTerminating,
		},
	}
	if namespace.Status.Phase != api_v1.NamespaceTerminating {
		nc.eventRecorder.Event(namespace, api.EventTypeNormal, "DeleteNamespace", fmt.Sprintf("Marking for deletion"))
		_, err := nc.federatedApiClient.Core().Namespaces().Update(updatedNamespace)
		if err != nil {
			return fmt.Errorf("failed to update namespace: %v", err)
		}
	}

	// Right now there is just 5 types of objects: ReplicaSet, Secret, Ingress, Events and Service.
	// Temporarly these items are simply deleted one by one to squeeze this code into 1.4.
	// TODO: Make it generic (like in the regular namespace controller) and parallel.
	err := nc.federatedApiClient.Core().Services(namespace.Name).DeleteCollection(&api_v1.DeleteOptions{}, api_v1.ListOptions{})
	if err != nil {
		return fmt.Errorf("failed to delete service list: %v", err)
	}
	err = nc.federatedApiClient.Extensions().ReplicaSets(namespace.Name).DeleteCollection(&api_v1.DeleteOptions{}, api_v1.ListOptions{})
	if err != nil {
		return fmt.Errorf("failed to delete replicaset list from namespace: %v", err)
	}
	err = nc.federatedApiClient.Core().Secrets(namespace.Name).DeleteCollection(&api_v1.DeleteOptions{}, api_v1.ListOptions{})
	if err != nil {
		return fmt.Errorf("failed to delete secret list from namespace: %v", err)
	}
	err = nc.federatedApiClient.Extensions().Ingresses(namespace.Name).DeleteCollection(&api_v1.DeleteOptions{}, api_v1.ListOptions{})
	if err != nil {
		return fmt.Errorf("failed to delete ingresses list from namespace: %v", err)
	}
	err = nc.federatedApiClient.Extensions().DaemonSets(namespace.Name).DeleteCollection(&api_v1.DeleteOptions{}, api_v1.ListOptions{})
	if err != nil {
		return fmt.Errorf("failed to delete daemonsets list from namespace: %v", err)
	}
	err = nc.federatedApiClient.Extensions().Deployments(namespace.Name).DeleteCollection(&api_v1.DeleteOptions{}, api_v1.ListOptions{})
	if err != nil {
		return fmt.Errorf("failed to delete deployments list from namespace: %v", err)
	}
	err = nc.federatedApiClient.Core().Events(namespace.Name).DeleteCollection(&api_v1.DeleteOptions{}, api_v1.ListOptions{})
	if err != nil {
		return fmt.Errorf("failed to delete events list from namespace: %v", err)
	}

	// Remove kube_api.FinalzerKubernetes
	if len(updatedNamespace.Spec.Finalizers) != 0 {
		finalizerSet := sets.NewString()
		for i := range namespace.Spec.Finalizers {
			if namespace.Spec.Finalizers[i] != api_v1.FinalizerKubernetes {
				finalizerSet.Insert(string(namespace.Spec.Finalizers[i]))
			}
		}
		updatedNamespace.Spec.Finalizers = make([]api_v1.FinalizerName, 0, len(finalizerSet))
		for _, value := range finalizerSet.List() {
			updatedNamespace.Spec.Finalizers = append(updatedNamespace.Spec.Finalizers, api_v1.FinalizerName(value))
		}
		_, err := nc.federatedApiClient.Core().Namespaces().Finalize(updatedNamespace)
		if err != nil {
			return fmt.Errorf("failed to finalize namespace: %v", err)
		}
	}

	// TODO: What about namespaces in subclusters ???
	err = nc.federatedApiClient.Core().Namespaces().Delete(updatedNamespace.Name, &api_v1.DeleteOptions{})
	if err != nil {
		// Its all good if the error is not found error. That means it is deleted already and we do not have to do anything.
		// This is expected when we are processing an update as a result of namespace finalizer deletion.
		// The process that deleted the last finalizer is also going to delete the namespace and we do not have to do anything.
		if !errors.IsNotFound(err) {
			return fmt.Errorf("failed to delete namespace: %v", err)
		}
	}
	return nil
}